Electronic clock radio having nap/sleep feature

ABSTRACT

An electronic clock radio using a clock integrated circuit and a radio integrated circuit. A first energizing potential when applied to the NAP/SLEEP input connection of the clock circuit, causes the clock circuit to switch from a first electric state to a second electric state. After a selected interval of time, not greater than 60 minutes, the clock circuit switches from the second electric state to the first electric state. The radio, normally in an OFF state is placed in an ON state only upon receiving a second energizing potential applied to its input connection. A control circuit, having a manually operable switch with NAP and SLEEP positions and being responsive to the electric states of the clock circuit, connects this second energizing potential to the radio input only when: 
     (i) the manually operable switch is in the NAP position and the clock circuit is the first electric state, or 
     (ii) the manually operable switch is in the SLEEP position and the clock circuit is in the second electric state.

BACKGROUND OF THE INVENTION

This invention relates to electronic clock radios using large scaleintegration and to the NAP or SNOOZE features provided in such radios.

Many consumer oriented electronic clock radios essentially consist ofthree integrated circuits (IC's) : a radio, a clock, and an electronicdigital display. An AC-to-DC voltage regulator, which provides thecorrect bias voltages to the IC's may or may not be included as anintegrated device. The remaining circuitry in the clock radio consistsof IC interconnections and interface components.

Included in the various features which such commercial radios provide isthe SLEEP function. The SLEEP function is initiated by a SLEEP switchwhich activates the radio for a selected time interval, usually 1 to 60minutes. At the end of this time period the radio automatically turnsOFF. Another standard feature is the WAKE-UP ALARM which automaticallyturns the radio ON (or activates a buzzer) when the displayed time and apreselected time setting coincide. Associated with the WAKE-UP ALARMfeature is the NAP (also called SNOOZE) function. Once the ALARM circuithas turned the radio ON, the NAP switch can shut the radio OFF for somestandard time interval--usually 9 to 10 minutes. The intended purpose ofthe NAP function is to allow the user to sleep or rest for a shortinterval after the alarm has sounded or after the radio has beenactivated.

Since the NAP feature can only be used in conjunction with the WAKE-UPALARM, its use is limited to a very specific time of day unless the 24hour alarm setting is changed. And, it is undesirable to disturb thisalarm setting since the user might forget to reset the alarm timesetting and fail to be awakened at the usual time. This generallyprecludes the use of the NAP function at any other time, or for any restperiod other than the built-in interval of 9 to 10 minutes.

OBJECTS AND SUMMARY OF THE INVENTION

It is an object of this invention to provide a NAP function in anelectronic clock radio that does not have to be used in conjunction withthe WAKE-UP ALARM.

It is another object of this invention to incorporate into an integratedclock radio a NAP feature having an adjustable NAP time period withoutadding a separate timing circuit just for this function.

In accordance with one embodiment of this invention a clock integratedcircuit and a radio are electrically connected via a control circuit. Afirst energizing potential applied to the NAP/SLEEP input connection ofthe IC, causes the clock to switch from a first electric state to asecond electric state. After a selected interval of time, the clockswitches from the second electric state to the first electric state. Theclock IC also includes a provision for selecting this interval of timefor periods not greater than 60 minutes. The radio, normally in an OFFstate is placed in an ON state only upon receiving a second energizingpotential applied to its input connection. The control circuit, having amanually operable switch with NAP and SLEEP positions and beingresponsive to the electric states of the clock, connects this secondenergizing potential to the radio input only when:

(i) the manually operable switch is in the NAP position and the clock isin the first electric state, or

(ii) the manually operable switch is in the SLEEP position and the clockis in the second electric state.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a schematic diagram which illustrates one embodiment ofthis invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

The major part of an electronic clock radio is shown in block form inFIG. 1 with many of the normal circuit interconnections removed sincetheir presence and operation are not relevant to this invention. ClockIC 20 provides all the necessary logic circuitry for the time-keepingfunction of a digital clock radio. Such devices are widely availablecommercially, e.g., Digital Alarm Clock, part No. S1998, andmanufactured by American Micro-Systems, Inc., would satisfy therequirements of clock 20. The clock devices 20 is powered by anenergizing potential, usually a positive DC voltage, which connects toimput terminal 14. This provides the necessary substrate voltage, V_(SS)to the device. The other IC supply voltage input, V_(DD), is connectedto a ground reference potential 15. Outputs 13 connect to a digitaldisplay device not shown in FIG. 1. Output 12 is the SLEEP outputconnection which is usually associated with the SLEEP function discussedabove. Switch S2 is used to activate this functional output. Bymementarily connecting terminal 11 to V_(SS), clock output terminal 12changes from an open circuit condition to a V_(SS) voltage, for apredetermined time.

In prior clock radio applications output 12 would be connected to aninterface circuit, which would supply an energizing potential to radio21 so long as terminal 12 exhibits the V_(SS) state. (The power handlingcapability of output 12 is insufficient to drive the radio directly). Aninterface circuit which is capable of energizing radio 21, is thetransistor Q2-Q3 combination. Typically, terminal 12 would be connectedto the base of Q2 through resistor R4. With terminal 12 in theopen-circuit state, the Q2 base voltage would be insufficient to forwardbias Q2. Hence, both Q2 and Q3 would be biased OFF and Q3 would notconduct an energizing potential (V_(SS)) to radio 21. As described, thiswould be the typical operation of a circuit providing a SLEEP function.

FIG. 1, however, shows other components connected to output terminal 12,namely, resistors R1-R3, transistor Q1 and switch S3. This addedcircuitry converts the usual SLEEP function of the clock radio to anoptional NAP/SLEEP function having the desired features. With switch S3connected to terminal 16, S2 immediately activates the radio for thepreselected time interval, and the combination provides the usualfeatures of a SLEEP function. However, with S3 connected to terminal 17,the functional sense of the interface circuitry is inverted. When S2 isdepressed, terminal 12 changes to V_(SS). This causes the base-emitterjunction of Q1 to be reversed biased, which causes Q1 to be OFF. With Q1OFF, both Q2 and Q3 will be OFF due to a lack of base bias current. WhenQ3 is OFF, radio 21 will be OFF. After the selected time intervalelapses, terminal 12 changes to an OPEN circuit allowing current to flowthrough voltage divider R1, R2 and R3. The base-emitter of Q1 becomesforward biased and Q1 turns ON. This provides bias current to Q2 and Q3,and hence, radio 21 is switched ON. This is precisely the desiredoperation of the NAP function. Summarizing the NAP operation, when S2 isdepressed, radio 21 turns OFF for the present time interval. When thistime interval, has elapsed, radio 21 turns ON. Therefore, depending onthe position of switch S3, switch S2 becomes either a SLEEP switch or aNAP switch.

The procedure for selecting the desired time interval for the NAPfunction is the same procedure for selecting the SLEEP function. When S1is depressed, causing V_(SS) to be applied to input terminal 10, thedigital display will cycle from 1 to 60 minutes until the switch isreleased. When S1 is released, the time interval setting at that pointwill remain for both the NAP and SLEEP functions since either functionis activated with switch S2.

What is claimed is:
 1. Apparatus comprising:a clock integrated circuithaving a clock input connection to which a first energizing potentialmay be applied and an output connection, said circuit also having firstand second mutually exclusive electric states, said circuit normallybeing in said first state and being placed in said second state for aselected interval of time after said first potential is applied to saidclock input connection, said circuit including means for selecting theduration of said interval for time intervals not greater than 60minutes; a radio having a radio input connection and normally being inan OFF state, said radio being placed in an ON state upon receiving asecond energizing potential applied to said radio input connection;NAP/SLEEP switch means connected to said clock circuit input connectionfor supplying said first energizing potential to said clock; and controlmeans including a two position manually operable switch and beingconnected to said radio input connection, said control means when saidswitch is in one position supplying said second potential to said radioinput when said clock circuit is in the first state, and said controlmeans when said switch is in the other position also supplying saidsecond potential to said radio input when said clock circuit is in saidsecond state, wherein said control means further comprises: a groundpotential terminal; a first terminal for connection to a source ofenergizing potential; a first transistor having a base, emitter, andcollector, said emitter being connected to said first terminal; a secondtransistor having a base, emitter and collector, said collector of saidsecond transistor being connected to said first terminal; a thirdtransistor having a base, emitter and collector, said collector of saidthird transistor being connected to said first terminal, said base ofsaid third transistor being connected to said emitter of said secondtransistor, and said emitter of said third transistor being connected tosaid radio input; said manually operable switch having a common terminaland first and second switch terminals, said first switch terminal beingconnected to said clock output and said second switch terminal beingconnected to said collector of said first transistor; a first resistorconnected between said first terminal and said base of said firsttransistor; a second resistor connected between said base of said firsttransistor and said clock output; a third resistor connected betweensaid clock output and said ground potential; and a fourth resistorconnected between the common terminal of said switch and said base ofsaid second transistor.